Automatically-locking pulley device.



No. 772,885. PATENTED 0011s, 1904.

' I J .G. 'HOU GHTOIN.

AUTOMATICALLY LOCKING PULLEY DEVICE.

NO MODEL.

J l W T5 Inemr James C Holly/Non.

WRHCSSCB fv 1 mm T0 00% whom, it floaty concern:

a compact, durable, and inexpensive automat- UNITE I STATES Patented October 18, 1904.

PATENT OFFIC JAMES C. HOUGHTON, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO JOHN R. HILL, OF WASHINGTON, DISTRICT OF COLUMBIA.

AUTOMATICALLY-LOCKING PULLEY DEVICE.

SPECIFICATION forming part of Letters Patent No. 772,885, dated October 18, 1904.

Application filed August 5, 1904.

Be it known that I, J AMES C. HOUGHTON, a citizen of the United States, residing at VVashington, in the District of Columbia, have invented certain new and useful Improvements in Automatically-Locking Pulley Devices, of which the following is a specification.

My invention relates to an automaticallylocking pulley device especially adapted for a curtain-cord holder; and it consists in the constructions, combinations, and arrangements herein described and claimed.

The objects of my invention are to provide ically-locking device, which shall be simple and certain in its action.

Referring to the accompanying drawings, forming a part of this application, and in which similar reference-numerals indicate corresponding parts in the several views, Figure 1 is a front elevation of a preferred form of my invention. Fig. 2 is a perspective View, on a larger scale, of the drum or pulley shown in Fig. 1. Fig. 3 is a front elevation of a modified construction, in which either end of the drum is provided with a spiral cam-groove for locking the cord; and Fig. 4 is a top plan view of the construction shown inFig. 3.

Referring especially to Figs. 1 and 2, 1 in dicates a bracket provided with lugs 2, constituting journaled supports for a drum 3 and with screw-openings 4; for securing it to a window-frame or other desired support.v A shifting-piece 5. provided with adirecting-slot 6, is pivotally supported to the bracket for movement between two shoulders 7 and 8' thereon, any suitable means,such as a spring 9, (shown in Fig. A) being provided for normally maintaining the shifting-piece against one of said shoulders.

The drum 3, journaled in the lugs 2, is provided with a concentric groove 10 and with a spiral cam-surface 11 leading from the bottom of said groove 10, and at its point of greatest radiance approximating theunder surface of a clamping-lug 13 on the bracket, a portion of said cam-surface being preferably roughened, as shown at 12. v I

In the employment of my invention the supporting cord or cable is passed through the-- Serial No. 219,657. (No model.)

slot 6 and attached to the curtain or other load which is to be supported thereon. .As shown in Fig. 1, the shifting-piece 5 is normally maintained in position to direct the cord onto the cam-surface 11, whereby the cord is sesurely gripped between said surface and the lug 13 to prevent descent of the curtain or other load suspended thereon.

When it is desired to vary the position of the curtain, the operator draws the free end of the cord to the left and forward sufficiently to shift said cord from the spiral cam-surface into the concentric groove 10. The operator then maintains the tension of the free end of the cord toward the left sufficiently to hold the shifting-piece 5 against the action of the spring 9 with its directing-slot 6 in registry with the concentric groove 10, and with the parts in this position the curtain can be raised or lowered, as desired, by drawing on or loosening the free end of the cord. When the curtain has been adjusted to the desired position, the operator relieves the tension toward the left on the free end of the cord, thereby permitting the shifting-piece 5 to be automatically returned by the spring 9 to its normal position, as shown in Fig. .1. In this position of the parts the slot 6 will direct the cord onto the spiral cam-surface 11 and upon slight turning of the drum the cord will be clamped between such surface and the clamping-lug 13 to support the curtain in its adjusted posit-ion.

Figs. 3 and 4 illustratea modified construction, in which the drum is providedwith a spiral cam-surface 14:, similar to the surface 11 of Figs. 1 and 2, on each side of a medial concentric groove 15, thereby providing a construction whereby the cord can be clamped either by drawing it to the left or by permitting the shifting-piece 5 to direct it to the right.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In an automatically-locking pulley device, the combination of a clamping-lug, a drum provided with a cam-surface in cooperative relation to said lug, movable means constructed to direct a cord over said drum, and means constructed to normally maintain said directing means in registry with said camsurface, substantially as described.

2. In an automatically-locking pulley device, the combination of a clamping-lug, a drum provided with a cam-surface in cooperative relation to said lug, movable means constructed to direct a cord over said drum, and resilient means constructed to normally maintain said directing means in registry with said cam-surface, substantially as described.

3. In an automatically-loeking pulley device, the combination of a clamping-lug, a drum provided with a concentric groove and With a spiral cam-surface leading from said groove and arranged in cooperative relation With said clamping-lug, movable means constructed to direct a cord over said drum, and means constructed to normally maintain said directing means in registry with said camsurface, substantially as described.

4. In an automatically-locking pulley device, the combination of a clamping-lug, a drum provided with a concentric groove and With a spiral cam-surface leading from said groove and arranged in cooperative relation with said clamping-lug, movable means constructed to direct a cord over said drum, and resilient means constructed to normally maintain said directing means in registry with said cam-surface, substantially as described.

5. In an automatically-locking pulley device, the combination of a bracket provided with a clamping-lug, and with shoulders or abutments, a shifting-piece pivotally secured by its extent of swing is limited thereby, a spring constructed to normally maintain said shifting-piece against one of said shoulders, and a drum journaled in said bracket and provided with a cam-surface in eorlperative relation with said clamping-lug, substantially as described.

6. In an automatically-locking pulley device, the combination of a bracket provided with a clai'nping-lug. a drum journaled in said bracket and provided with a concentric groove and with a spiral cam-surface leading from said groove and arranged in cooperative relation with said clamping-lug, a shitting-piece pivotally secured to said bracket and provided with a slot for directing a cord over said drum, shoulders on said bracket constructed to so limit the swing of the pivoted piece that in its two extreme positions its directing-slot will register, respectively, with said concentric groove and said cam-surface, and means constructed to normally maintain said shittingpiece in position to bring its slot into registr with said cam-surface, substantially as described.

In testimony whereof I al'lix my signature in presence of two witnesses.

JAMES C. llOU(ill'l(p)N.

Vitnesses:

LYMAN Ii. ELLIS, Epwann M. \Vrznus. 

